Submission #792322

#	Time	Username	Problem	Language	Result	Execution time	Memory
792322		cig32	Naboj (COCI22_naboj)	C++17	110 / 110	170 ms	33828 KiB

naboj

#include "bits/stdc++.h"
using namespace std;
#define int long long
const int MAXN = 2e5 + 10;
const int MOD = 1e9 + 7;
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
int bm(int b, int p) {
  if(p==0) return 1 % MOD;
  int r = bm(b, p >> 1);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
int inv(int b) { 
  return bm(b, MOD-2);
}
int fastlog(int x) {
  return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void printcase(int i) { cout << "Case #" << i << ": "; }
int n, m;
vector<int> adj[MAXN];
int K[MAXN];
bool vis[MAXN];
stack<int> topsort;
void dfs(int node) {
  vis[node] = 1;
  for(int x: adj[node]) {
    if(!vis[x]) {
      dfs(x);
    }
  }
  topsort.push(node);
}
void solve(int tc) {
  cin >> n >> m;
  vector<pair<int, int> > constraints;
  for(int i=1; i<=m; i++) {
    int a, b;
    cin >> a >> b;
    constraints.push_back({a, b});
    adj[b].push_back(a);
  }
  for(int i=1; i<=n; i++) {
    if(!vis[i]) {
      dfs(i);
    }
  }
  for(int i=1; i<=n; i++) {
    K[topsort.top()] = i;
    topsort.pop();
  }
  for(pair<int, int> X: constraints) {
    if(K[X.first] < K[X.second]) {
      cout << "-1\n"; return;
    }
  }
  int pos[n+1];
  for(int i=1; i<=n; i++) pos[K[i]] = i;
  cout << n << "\n";
  for(int i=1; i<=n; i++) {
    cout << pos[i] << " 1\n";
  }

}
int32_t main() {
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}
// 勿忘初衷

• Subtask 1: 15 / 15
• Subtask 2: 25 / 25
• Subtask 3: 70 / 70